Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Often, trace impurities or other contamination in a material can result in a measurable change in the refractive index value of the material. Consequently, measurement of the refractive index of a material can accurately quantify the presence of such impurities or contamination, particularly in liquids. For example, the refractive index value of liquids or solids can be measured with refractometers, which measure some angle of refraction or the critical angle for total internal reflection of a material. Refractometers are commonly employed for the identification of substances and for quality control of various products, such as wine, sugar, pharmaceuticals, and the like.